Generally, an engine room is provided on a front part of a vehicle and a hood is provided openable in the engine room. The hood serves to open or close the engine room and block engine noise by shielding the engine room wherein both left and right sides of a rear part of the hood are connected to a top of the engine room through a hood hinge assembly and the hood is rotated around the hood hinge assembly to open or close the engine room.
A hood is connected firmly and thus when a walker collides with a front part of a vehicle, a large injury is made to the walker as a part of a body such as head of the walker collides with the hood. Accordingly, recently an active hood system is applied thereto, which can ensure a space between the hood and the engine room for absorbing impact energy of the walker when collision occurs.
The active hood system is a safety device for protecting a walker, which can dampen the impact applied to the walker from a rear part of a hood (or hood hinge assembly) and at the same time reduce injury degree when collision occurs wherein when a sensor on a front bumper detects a walker collision if a walker collides with the front bumper, a controller operates an actuator according to a detection signal from the sensor to raise a rear part of the hood, thereby ensuring a dampening space between the hood and the engine room.
However, when the active hood system is malfunctioned due to a failure of a collision detection sensor, the impact applied to a walker cannot be absorbed through the active hood system when a walker collision occurs and the injury to the walker is aggravated.
In order to solve the drawbacks in the forgoing a technology of Korean Patent No. 10-1241017, entitled “Hood Hinge Device For Reducing Walker Injury”, has been proposed. According to the conventional art, the hood hinge device includes: a hinge arm that is supported rotatably on a rear part of a hood; a hinge bracket that receives load of the hood through the hinge arm; a damping spring that supports elastically a lower part of the hinge bracket; a wedge bracket that is fixed a vehicle body; and a hinge wedge that connects or disconnects the hinge bracket to or from the wedge bracket depending on whether the hood is opened or closed wherein in a closed state of the hood the hinge bracket is separated from the wedge bracket to absorb impact load through the damping spring when a walker collies, and in an opened state of the hood the hinge bracket is connected to the wedge bracket to support the load of the hood that is transmitted through the hinge bracket so that the injury to a walker can be reduced through a damping structure embedded in a lower part of the hood hinge section and further the collected load of the hood is supported by the hinge wedge when the hood is opened, thereby reducing the injury to the walker who can secure basic performance of the hood at an ordinary day.
Accordingly, in order to meet to a walker protection regulation that is recently reinforced and respond to commerciality of a vehicle an active hood system that serves to reduce the injury to a head form by popping-up the hood is opened and mass-produced as a walker protection technology, however, cost and weight thereof are excessive so that other systems need to be developed. As a result, a passive hood technology has been developed, in which a hood is lowered to reduce the injury degree of a walker when the walker collides with a vehicle, however, there arise problems in that the injury to a walker is accelerated as the performance of a sensor for recognizing the impact applied to the walker is instable or malfunctioned and the size and weight thereof are excessive and thus it is difficult to ensure the space thereof and increase cost.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.